The present invention is for the kind of power machines, engines, pumps or compressors which have two or more pistons which work against each other, preferably with a common combustion space in a stationary cylinder and where the power is transmitted to or from a rotating motion without an intermediate crankshaft.
There are special problems with the lubrication of the parts of the power transmission without having to equip the device with complicated and costly auxiliary systems.
In combustion engines the transmission of power from a to and fro (i.e., reciprocating) motion to a rotating motion generally is by means of some kind of crankshaft or the like device. In some cases however, crankshafts are less suitable, and this is especially the case when to and fro motions of different, often directly opposite directions, together shall be transmitted to a rotating motion. Especially this holds for the kind of power machines i.e. combustion engines, compressors and pumps where two pistons at the same time work against each other in a common cylinder bore. The use of crankshaft in these cases brings with it complicated mechanical designs in order to join the power from the two pistons to a common rotating motion. The transmission of power between a to and fro motion and a rotating motion may instead take place by means of a ballbearing which runs in several tracks and comprises a ball which is surrounded by a ballholder which is attached to a piston rod or corresponding device for each ball for transmission of the linear motion to a rotating motion. It is also possible to substitute the balls for other means with corresponding function, for example rolls or pins which roll or slide in the tracks.
One such device has two parallel plane discs, both a stationary disc and one relatively thereto rotating disc. In a cylinder which is positioned centrally relative to the discs there are two pistons which are working pistons in a combustion engine having a common combustion chamber. Permanently joined to each piston is a piston rod which in its opposite end has a holder means for the ball by means of which the power from the to and fro motion is transmitted to the rotating disc. The balls also serve as bearing between the stationary disc and the rotating disc. The rotating disc is mounted to a holder which in its turn is mounted onto an outgoing shaft from which the rotating power is taken for use for various driving purposes. The balls can move both in linear tracks in the fixed disc and in a common elliptic or otherwise closed shaped track in the rotating disc. It is also possible to substitute the balls for other means having a corresponding function, for example rolls or pins which roll or slide in the tracks. In other embodiments the tracks can be substituted for by raised edges forming contact surfaces for e.g. roller or slide bearings on the sides of the edge.
It is important for the function of the device that there is a satisfactory lubrication between the ball and holder and between the ball and the tracks wherein the balls move, or other means having corresponding functions.